The damage from a minimum wage hike depends on the overall labor market. If the job market is buoyant, as it is in the fracking boomtown of Williston, N.D., fast-food workers may already make more than $9 an hour. But when the jobless rate is high, as it still is in California and New York, the increase punishes minority youth in particular.

That is what happened during the last series of wage hikes to $7.25 from $5.15 that started in July 2007 as the economy was headed toward recession. The last increase hit in July 2009 just after the recession ended, and as the nearby chart shows, the jobless rate jumped for teens and black teens especially. For black teens, the rate has remained close to 40% and was still 37.8% in January.

A study by economists William Even of Miami University and David Macpherson of Trinity University concludes that in the 21 states where the full 40% wage increase took effect, “the consequences of the minimum wage for black young adults without a diploma were actually worse than the consequences of the Great Recession.”

William Dunkelberg, chief economist for the National Federation of Independent Business, says that after the July 2009 increase 600,000 teen jobs disappeared in the next six months even as GDP expanded. In the previous six months, when the economy was still shrinking, half as many teen jobs were lost. The overall teen jobless rate was still 23.4% last month, which means demand for unskilled workers is low even at $7.25 an hour. Demand will be lower at $9.

But today, a full-time worker making the minimum wage earns $14,500 a year. Even with the tax relief we’ve put in place, a family with two kids that earns the minimum wage still lives below the poverty line. That’s wrong.

He left out that most minimum-wage earners are not the primary bread winner. Nearly 40% live with a parent or relative. The average family income of a household with a minimum-wage worker is about $47,023—which is far above the poverty line of $23,550 for a family of four.

Mr. Obama didn’t even tell the whole story about parents raising a family on a minimum-wage income. A full-time minimum-wage worker earns roughly $15,000 a year. But that worker also receives a cash supplement from the earned income tax credit of roughly $5,000, and many states provide benefits on top of that to reward working. That doesn’t count government benefits like food stamps, Medicaid, child care and more. According to data from the Employment Policies Institute, about two of every three minimum-wage workers also get a raise within one year.

There’s also the erroneous premise that people are forever stuck at minimum wage, when, in fact, minimum wage jobs are entry-level jobs where workers gain the experience they need to advance. More on that in the video: